Noise-free real time ultrasonic imaging of a treatment site undergoing high intensity focused ultrasound therapy

ABSTRACT

Method and apparatus for the simultaneous use of ultrasound on a probe for imaging and therapeutic purposes. The probe limits the effects of undesirable interference noise in a display by synchronizing high intensity focused ultrasound (HIFU) waves with an imaging transducer to cause the noise to be displayed in an area of the image that does not overlap the treatment site. In one embodiment, the HIFU is first energized at a low power level that does not cause tissue damage, so that the focal point of the HIFU can be identified by a change in the echogenicity of the tissue caused by the HIFU. Once the focal point is properly targeted on a desired treatment site, the power level is increased to a therapeutic level. The location of each treatment site is stored and displayed to the user to enable a plurality of spaced-apart treatment sites to be achieved. As the treatment progresses, any changes in the treatment site can be seen in the real time, noise-free image. A preferred application of the HIFU waves is to cause lesions in blood vessels, so that the supply of nutrients and oxygen to a region, such as a tumor, is interrupted. The tumor will thus eventually be destroyed. In a preferred embodiment, the HIFU is used to treat disorders of the female reproductive system, such as uterine fibroids. The HIFU treatment can be repeated at spaced-apart intervals, until any remaining fibroid tissue is destroyed.

RELATED APPLICATIONS

[0001] This application is based on U.S. provisional patent applicationSerial No. 60/100,812; filed on Sep. 18, 1998, the benefit of the filingdate of which is hereby claimed under 35 U.S.C. §119(e).

GOVERNMENT RIGHTS

[0002] This invention was made under contract with the United StatesDepartment of Defense, under Contract Number N00014-96-0630, and theUnited States government may have certain rights in the invention.

FIELD OF THE INVENTION

[0003] The present invention relates to ultrasonic imaging and therapyapparatus and method incorporating both ultrasonic observation andtherapeutic waves, and more specifically to apparatus and methoddesigned to allow real time, noise-free imaging of a treatment site towhich high intensity focused ultrasound is directed.

BACKGROUND OF THE INVENTION

[0004] Ultrasound has gained acceptance as an imaging techniqueparticularly well suited to providing information about a patient'sinternal structures without risk of exposure to potentially harmfulradiation, as may occur when using X-ray imaging techniques. The firstrecorded use of ultrasound as an imaging technique was by Dr. KarlDussik, a Psychiatrist at the hospital in Bad Ischl, Austria; who triedto locate brain tumors using ultrasound. He used two opposed probes,including one that transmitted ultrasound waves, while the other probereceived them. With these probes, he transmitted an ultrasound beamthrough a patient's skull, and used the received signal to visualize thecerebral structure by measuring the ultrasound beam attenuation. Hepublished his technique in 1942, in an article entitled,“Hyperphonography of the Brain.”

[0005] Specially manufactured medical diagnostic equipment usingultrasound became available in the 1950's. An ultrasound examination isa safe diagnostic procedure that uses very high-frequency sound waves toproduce an image of the internal structures of the body. Many studieshave shown that these sound waves are harmless and may be used withcomplete safety, even on pregnant women, where the use of X-rays wouldbe inappropriate. Furthermore, ultrasound examinations are sometimesquicker and typically less expensive than other imaging techniques.

[0006] More recently, the use of high intensity focused ultrasound(HIFU) for therapeutic purposes, as opposed to imaging, has receivedsignificant attention in the medical community. HIFU therapy employsultrasound transducers that are capable of delivering 1,000-10,000 W/cm²at a focal spot, in contrast to diagnostic ultrasound where intensitylevels are usually below 0.1 W/cm². A portion of the mechanical energyfrom these high intensity sound waves is transferred to the targetedlocation as thermal energy. The amount of thermal energy thustransferred can be sufficiently intense to cauterize tissue, or to causetissue necrosis (by inducing a temperature rise to beyond 70° C.)without actual physical charring of the tissue. Tissue necrosis can alsobe achieved by mechanical action alone (i.e., by cavitation that resultsin mechanical disruption of the tissue structure). Further, where thevascular system supplying blood to an internal structure is targeted,HIFU can be used to induce hemostasis. The focal point of this energytransfer can be tightly controlled so as to obtain tissue necrosis in asmall target area without damaging adjoining tissue. Thus, deep-seatedtumors can be destroyed with HIFU without surgical exposure of the tumorsite.

[0007] A particular advantage of HIFU therapy over certain traditionaltherapies is that HIFU is less invasive. The current direction ofmedical therapy is progressively toward utilizing less-invasive andnon-operative approaches, as will be evident from the increasing use oflaparoscopic and endoscopic techniques. Advantages include reduced bloodloss, reduced risk of infection, shorter hospital stays, and lowerhealth care costs. HIFU has the potential to provide an additionaltreatment methodology consistent with this trend by offering a method ofnon-invasive surgery. HIFU enables transcutaneous tumor treatmentwithout making a single incision, thus avoiding blood loss and the riskof infection. Also, HIFU therapy may be performed without the need foranesthesia, thereby reducing surgical complications and cost. Mostimportantly, these treatments may be performed on an outpatient basis,further reducing health care cost, while increasing patient comfort.

[0008] The use of HIFU for the destruction of tumors is a relatively newtechnique. The first clinical trials were performed on patients withhyperkinetic and hypertonic disorders (symptoms of Parkinson's disease).HIFU was used to produce coagulation necrosis lesions in specificcomplexes of the brain. While the treatment was quite successful,monitoring and guidance of the HIFU lesion formation was not easilyachieved (N. T. Sanghvi and R. H. Hawes, “High-intensity focusedultrasound,” Gastrointestinal Endoscopy Clinics of North America, vol.4, pp. 383-95, 1994). The problem has been that the high energytherapeutic wave introduces a significant amount of noise into anultrasound imaging signal employed to monitor the treatment site, makingsimultaneous imaging and treatment difficult. Indeed, the high energy ofthe HIFU can completely overwhelm conventional ultrasonic imagingsystems. However, the advancement of imaging modalities has providedgrounds for renewed research and development of HIFU-based tumortreatment methods. In general, current methods involve the use ofdiscrete imaging and therapeutic steps, i.e., a treatment site is firstimaged, therapy is applied, and the treatment site is again imaged. Thetherapeutic transducer is de-energized during the imaging process toeliminate the noise it would otherwise produce. However, the timerequired for carrying out each of these discrete steps has prevented thesignificant potential of HIFU from being fully realized, since real-timeguidance and monitoring of HIFU has not been achieved.

[0009] Two HIFU-based systems have been developed for the treatment ofbenign prostatic hyperplasia (BPH) in humans (E. D. Mulligan, T. H.Lynch, D. Mulvin, D. Greene, J. M. Smith, and J. M. Fitzpatrick,“High-intensity focused ultrasound in the treatment of benign prostatichyperplasia,” Br J Urol, vol. 70, pp. 177-80, 1997). These systems arecurrently in clinical use in Europe and Japan, and are undergoingclinical trials in the United States. Both systems use a transrectalHIFU probe to deliver 1,000-2,000 W/cm² to the prostate tissue throughthe rectum wall. No evidence of damage to the rectal wall has beenobserved during a rectoscopy, performed immediately after HIFU treatment(S. Madersbacher, C. Kratzik, M. Susani, and M. Marberger, “Tissueablation in benign prostatic hyperplasia with high intensity focusedultrasound,” Journal of Urology, vol. 152, pp. 1956-60; discussion1960-1, 1994). Follow-up studies have shown decreased symptoms of BPH(i.e., increased urinary flow rate, decreased post-void residual volume,and decreased symptoms of irritation and obstruction; see S.Madersbacher, C. Kratzik, N. Szabo, M. Susani, L. Vingers, and M.Marberger, “Tissue ablation in benign prostatic hyperplasia withhigh-intensity focused ultrasound,” European Urology, vol. 23 Suppl 1,pp. 39-43, 1993). In this prior art use of HIFU, ultrasound imaging isemployed to obtain pre- and post-treatment maps of the prostate and thetreatment area. Significantly, the noise induced in the imaging signalby the HIFU prevents real time imaging of the treatment site. Therefore,strict imaging requirements, such as no patient movement during theentire procedure (thus, the need for general or spinal anesthesia),limit the performance of these systems. It should be noted thatrespiration alone can result in sufficient patient movement so that theHIFU is no longer targeted as precisely as would be desired. Especiallywhere the treatment site is adjacent to critical internal structuresthat can be damaged, the lack of real time imaging is a significantdrawback to an otherwise potentially very useful treatment methodology.

[0010] HIFU has also been studied for the de-bulking of malignant tumors(C. R. Hill and G. R. ter Haar, “Review article: high intensity focusedultrasound—potential for cancer treatment,” Br J Radiol, vol. 68, pp.1296-1303, 1995). Prostate cancer (S. Madersbacher, M. Pedevilla, L.Vingers, M. Susani, and M. Marberger, “Effect of high-intensity focusedultrasound on human prostate cancer in vivo,” Cancer Research, vol. 55,pp. 3346-51, 1995) and testicular cancer (S. Madersbacher, C. Kratzik,M. Susani, M. Pedevilla, and M. Marberger, “Transcutaneoushigh-intensity focused ultrasound and irradiation: an organ-preservingtreatment of cancer in a solitary testis,” European Urology, vol. 33,pp. 195-201, 1998) are among the cancers currently being investigatedclinically for potential treatment with HIFU. An extensive clinicalstudy to extracorporeally treat a variety of stage 4 cancers is underwayin England (A. G. Visioli, L. H. Rivens, G. R. ter Haar, A. Horwich, R.A. Huddart, E. Moskovic, A. Padhani, and J. Glees, “Preliminary resultsof a phase I dose escalation clinical trial using focused ultrasound inthe treatment of localized tumors,” Eur J Ultrasound, vol. 9, pp. 11-8,1999). The cancers involved include prostate, liver, kidney, hipbone,ovarian, breast adenoma, and ocular adenoma. No adverse effects, exceptone case of skin burn have been observed. Significantly, none of thesestudies has addressed the noise issue preventing the real time imagingof HIFU treatment.

[0011] U.S. Pat. No. 5,471,988 teaches the combination of a HIFU therapytransducer and an imaging transducer on the same probe. This patentpoints out that one of the problems with the prior art has beenobtaining scanning data in conjunction with the therapeutic operation ofthe probe, due to the noise that the therapeutic wave introduces intothe imaging signal. The reference notes that a problem withnon-simultaneous imaging is that in the time frame between when theimage was last seen, and when the therapy transducer is energized, it ispossible that the probe will move relative to a target area. Thus, thetherapeutic energy may be applied to an area that is not the desiredtarget. The patent teaches that it is desirable for the therapy andimaging transducers operate at different frequencies, e.g., 12 MHz forthe imaging transducer and less than 2 MHz for the therapeutictransducer. It is also suggested that incorporating noise reductioncircuitry in the imaging system can help to reduce the impact of theinterfering noise. Unfortunately, it has been determined that thisapproach does not work as effectively as would be desired.

[0012] U.S. Pat. No. 5,769,790 describes another combination probe thatincludes transducers for both ultrasonic imaging and treatment. Thispatent teaches that prior to the delivery of therapy, verification ofthe focal point of the therapeutic wave is needed and advocatesenergizing the therapy transducer at a relatively low power level andusing the imaging transducer to detect the low power ultrasound wavesproduced by the therapy transducer that are reflected from the targetsite. This technique provides a B-mode image where the only area in theimage to be significantly illuminated is the focus of the therapytransducer. The image frame can then be interleaved with or superimposed on a normal B-mode image frame where both transmit and receivefunctions are performed using the imaging transducer. Once the focalpoint of the therapy transducer has been verified in this manner,therapy can be delivered by applying higher power, longer durationexcitation to the therapy transducer. Significantly, the '790 patentdoes not teach the simultaneous scanning of the treatment area with theultrasonic signal transmitted by the imaging transducer while thetherapy transducer is operational, nor does the '790 patent discuss howthe noise problem can be addressed.

[0013] U.S. Pat. No. 5,895,356 is directed to a method and apparatusoptimized for the treatment of diseases of the prostate. This referenceteaches that the echogenicity of tissue heated to over 60° C. changes sothat when imaged using an ultrasonic imaging transducer, a bright spotappears in the viewing field, and that this echogenicity is transient(it fades with time). The patent also teaches storing the location ofthis region of higher echogenicity in a memory of an imaging system andsuperimposing the known focal point of the therapeutic transducer on thedisplay of the imaging system, so that the therapeutic transducer can befocused on an area of interest prior to energizing the therapeutictransducer. The patent teaches imaging using low power ultrasound,focusing using the known focal point, ceasing the imaging, applying ahigher power ultrasound therapy, ceasing the therapy, and then using lowpower ultrasound to generate an image of the area just treated.Significantly, the patent does not discuss how noise produced by thesimultaneous operation of imaging and therapeutic ultrasound can bereduced.

[0014] While the prior art has recognizes the advantages that real timeimaging can provide, a suitable method of achieving such imaging has notbeen described. It would be desirable to provide a method in whichsimultaneous imaging and therapy can be achieved in real time without anoise signal degrading the image quality of the treatment site.

[0015] Furthermore, there are many medical conditions that could benefitfrom simultaneous treatment and imaging using HIFU. In particular, itappears that the treatment of gynecological and obstetrical disorderscould be significantly enhanced. For example, uterine fibroids, whichare benign tumors of the uterus and are found in more than half of allwomen, could be treated using an image-guided HIFU therapy system.Approximately 30% of all hysterectomies are related to these uterinefibroids. Current treatment methods for uterine fibroids include bothdrug therapy and surgery. Drug therapy has virtually a 100% rate oftumor reoccurrence once the drug therapy has stopped, and the drugtherapy itself includes numerous negative side effects. The rate ofreoccurrence is significantly less (about 15%) for the surgical therapy,though the surgical procedure is invasive, requiring a significantrecovery period, and involves significant risks, such as blood loss,damage to related organs, and the ever present risk of infection. It isestimated that uterine fibroid procedures in the United States aloneaccount for 1.2 to 3.6 billion dollars in annual medical costs.

[0016] Thus, it would be desirable to develop simultaneous or real timeimaging and therapeutic ultrasound methods and apparatus. Initially,such methods and apparatus might be optimized for the treatment ofuterine fibroids, and other gynecological and obstetrical disorders.Such treatment is expected to compare favorably with the costs for thecurrent drug related therapy for the treatment of uterine fibroids andshould compare favorably with the higher success rate of the currentsurgical procedures, but without the attendant risks.

SUMMARY OF THE INVENTION

[0017] In accord with the present invention, a method is defined forusing ultrasound to simultaneously image a target area and to providetherapy to a treatment site within the target area in real time. Themethod employs a scanning ultrasonic transducer system adapted to scan atarget area and to provide imaging data for the target area, a processoradapted to manipulate the imaging data, a display capable of providing avisual representation of the imaging data to a user to produce adisplayed target area, and a therapeutic ultrasonic transducer systemadapted to provide pulsed waves of HIFU to the treatment site within thetarget area.

[0018] The method includes the steps of scanning the target area togenerate the imaging data, and displaying a visual representation of theimaging data. A treatment site is selected from within the displayedtarget area; and the therapeutic ultrasonic transducer system isenergized to produce the therapeutic waves. Synchronization of thetherapeutic ultrasonic transducer system relative to the scanningultrasonic transducer system is adjusted such that any noise within theimaging data arising from the therapeutic waves is shifted away from theimage of the treatment site. Thus, a noise-free image of the treatmentsite is provided.

[0019] In one embodiment, the therapeutic ultrasonic transducer systemis initially energized at a level that is not energetic enough toproduce a therapeutic effect at the treatment site, but is sufficientlyenergetic to produce a change in the echogenicity of tissue at thetreatment site. This change in echogenicity is detected by the scanningultrasonic transducer system, so that the focal point of the therapeuticultrasonic transducer system is clearly displayed, enabling thetherapeutic ultrasonic transducer system to be focused at a desireposition for the treatment site. Once properly focused, the energy levelof the pulsed therapeutic wave is increased to a therapeutic level thatis sufficiently energetic to produce a desired therapeutic effect.

[0020] In addition to monitoring for changes in the treatment site, therest of the target area can be monitored to detect any changes to anynon-treatment site area due to the HIFU. Such a change is undesirable,and when noticed, the therapeutic ultrasonic transducer system can bede-energized to prevent further changes to non-treatment site areas,even if the desired therapeutic effect has not yet been achieved at thetreatment site.

[0021] Preferably, the processor is capable of manipulating the imagingdata by effecting scan conversion processing, color flow processing,Doppler processing, B-mode processing or M-mode processing. In oneembodiment, the three-dimensional (3D) location of the previouslytreated sites are stored and appear on the display.

[0022] In one preferred embodiment, the target area is the reproductivesystem of a mammalian female, and the desired therapeutic effect isapplied to a uterine fibroid, an endometrial polyp, a follicular cyst, apolycystic ovary, a dermoid cyst, a corpus luteum cyst, an ectopicpregnancy, a cornual pregnancy, a multifetal pregnancy, a uterinemalformation, an endometrial hyperplasia, an adenomyosis condition, andendometriosis condition, or an excessive bleeding condition. Thetreatment of disorders of the female reproductive system using themethod of the present invention can be achieved by positioning thescanning ultrasonic transducer system and the therapeutic ultrasonictransducer system adjacent to the female reproductive system. Vaginal,rectal, abdominal, and laparoscopic approaches are contemplated.Accordingly, probes adapted for use in the vaginal canal and the rectumare also defined. Preferably, these probes incorporate both the scanningultrasonic transducer system and the therapeutic ultrasonic transducersystem. The methods include the step of inserting the probe into theappropriate cavity, and advancing the probe until the probe is adjacentto a target area before energizing the scanning ultrasonic transducersystem. The focal point of the HIFU is positioned on the pathologictissue.

[0023] In further embodiments using the above-described probes, the stepof energizing the therapeutic ultrasonic transducer system generatesfrequencies within the range of 0.5 MHz to 10 MHz. An even morepreferred range for the therapeutic ultrasonic transducer system is 1MHz to 3.5 MHz.

[0024] In one embodiment, the therapeutic ultrasonic transducer systemincludes a phased array that enables the focal point of the therapeuticultrasonic transducer system to be effectively enlarged. In anotherembodiment, the therapeutic ultrasonic transducer system comprises avibrating element that is energized to cause a focal point of thetherapeutic ultrasonic transducer system to be varied. The step ofenergizing the vibrating element causes the therapeutic ultrasonictransducer system to vibrate with a frequency in the range of 1 to 5 Hz,thereby avoiding the heating of tissue not associated with the treatmentsite in the unfocused regions of the HIFU beam. Alternately, thevibrating element causes the therapeutic ultrasonic transducer system tovibrate with a frequency in the range of 10 to 50 Hz, thereby increasingan amount of energy applied to the treatment site, while avoidingundesired cavitational effects.

[0025] The method enables HIFU to be used to cause the cauterization oftissue at the treatment site for arresting bleeding, preventingbleeding, or causing tissue necrosis. The HIFU can also be used to causethe necrosis of tissue at the treatment site by cavitation or thermaleffects, or to ablate tissue at the treatment site.

[0026] Another aspect of the present invention is a method for treatinga tumorous growth by damaging only selected regions within the tumorousgrowth. The steps of the method involve using the scanning ultrasonictransducer system to produce an image of the target area on the displayas a visual representation of the target area. A selected region fromwithin the tumorous growth is then selected as a treatment site.

[0027] The therapeutic ultrasonic transducer system is focused on theselected region until the desired level of damage is obtained. Adifferent region within the tumorous growth is selected; and the stepsare repeated until a desired pattern of damaged areas has been formed inthe tumorous growth. After waiting a period of time sufficient to allowthe macrophagic processes to remove necrotic tissue from the damagedareas, the treatment is repeated, until the tumorous growth issubstantially destroyed.

[0028] Another aspect of the present invention is directed to a systemfor simultaneously imaging and applying treatment using ultrasound. Thesystem includes elements that carryout functions generally correspondingto the steps of the methods discussed above.

BRIEF DESCRIPTION OF THE FIGURES

[0029] The foregoing aspects and many of the attendant advantages ofthis invention will become more readily appreciated as the same becomesbetter understood by reference to the following detailed description,when taken in conjunction with the accompanying drawings, wherein:

[0030] FIGS. 1A-1C respectively illustrate ultrasonic images generatedduring the simultaneous use of ultrasound for imaging and therapyaccording to the prior art, the pulsing of the HIFU in a conventionalscanned image, and the synchronized pulsing of the HIFU and the scanimage so as to shift the noise away from a displayed treatment site;

[0031]FIG. 2 is a block diagram illustrating the components of a systemcapable of the simultaneous use of ultrasound for imaging and therapy,in accord with the present invention;

[0032] FIGS. 3A(1)-3D(4) illustrate timing and synchronization patternsthat enable the simultaneous use of ultrasound for imaging and therapy;

[0033]FIG. 4 illustrates yet another timing and synchronization patternfor synchronizing the HIFU and imaging scans;

[0034]FIG. 5A is a schematic view of individual external imaging andtherapeutic ultrasonic transducers being used for the simultaneousimaging and treatment of a tumor in a female reproductive system, andFIG. 5B illustrates an ultrasonic image that would be thus generated;

[0035]FIG. 6 is a schematic view of a vaginal probe that includes bothimaging and therapeutic ultrasonic transducers being used for thesimultaneous imaging and treatment of a tumor in a female reproductivesystem;

[0036]FIG. 7 is a schematic view of a rectal probe that includes bothimaging and therapeutic ultrasonic transducers being used for thesimultaneous imaging and treatment of a tumor in a female reproductivesystem;

[0037]FIG. 8 is a schematic view of a prior art vaginal probe thatincludes an imaging transducer;

[0038]FIG. 9 is a schematic view of the distal end of a vaginal probeand FIG. 9B is a HIFU module adapted to be used in conjunction with thevaginal probe;

[0039]FIG. 10 is a schematic view of a HIFU module mounted onto thedistal end of a prior art vaginal probe;

[0040]FIG. 11 is a schematic view of a combination HIFU module and priorart vaginal probe, and an ultrasonic image produced thereby in which thefocal point of the HIFU module is displayed in a noise-free area of theimage, in accord with the present invention;

[0041]FIG. 12 is a schematic view of a second embodiment of a HIFUmodule combined with a prior art vaginal probe;

[0042]FIG. 13 is a cross-sectional view of the second embodiment of thecombination HIFU module and prior art vaginal probe, including a chamberin fluid communication with both the imaging and therapeutictransducers;

[0043]FIG. 14 is a schematic view of the second embodiment of thecombination HIFU module and prior art vaginal probe, including the fluidfilled chamber and the wave patterns of both the imaging and therapeutictransducers;

[0044]FIG. 15 is a schematic view of a third embodiment of a HIFU modulecombined with the prior art vaginal probe, including a chamber in fluidcommunication with only the therapeutic transducer;

[0045]FIG. 16 is a schematic view of therapeutic and imaging transducersintegrated into a vaginal probe that includes a paddle-shaped distalend;

[0046]FIG. 17 is a side elevational view of the integrated probe of FIG.16 illustrating how a position of the paddle-shaped head can be variedaround a pivot joint;

[0047]FIG. 18 is a schematic view of phased array therapeutic andimaging transducers of the integrated probe of FIG. 16, in which theimaging transducer is steerable, and the focal point of the therapeutictransducers is variable;

[0048]FIG. 19 is a schematic view of a different embodiment of apaddle-headed integrated probe similar to that of FIG. 16, in which theorientation of the imaging transducer has been shifted by 90°, thusshifting the scanning field by 90°;

[0049]FIG. 20 is a schematic view of a different embodiment of apaddle-headed integrated probe similar to that of FIG. 18, in which thetherapy transducer is steerable in the same plane as the imagingtransducer;

[0050]FIG. 21 is a schematic view of phased array therapeutic andimaging transducers of an integrated probe in which both the imagingtransducer and the therapy transducer are steerable along both theirlongitudinal and latitudinal axes; and

[0051]FIG. 22 is a schematic block diagram of a 3D imaging and HIFUtherapy system that enables the HIFU therapy to be applied at selectedtreatment sites in a 3D image of a target area.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0052] As noted above in the Background of the Invention, the prior arthas recognized that real time imaging of therapeutic HIFU would bebeneficial in a number of treatment methodologies. From a practicalstandpoint this is not proven easy to do, because the HIFU used fortherapy completely saturates the signal provided by the imagingtransducer. One analogy that might help to make this problem clearrelates to the relative intensities of light. Consider the light comingfrom a star in the evening sky to be equivalent to the low power imagingultrasound waves that are reflected from a target area toward theimaging transducer, while the light from the sun is equivalent to theHIFU generated by the therapy transducer. When the sun is out, the lightfrom the stars is completely overwhelmed by the light from the sun, anda person looking into the sky is unable to see any stars, because thebright light from the sun completely masks the dim light coming from thestars. Similarly, the HIFU emitted by the therapy transducer completelyoverwhelms the ultrasonic waves produced by the imaging transducer andany ultrasonic image generated is completely saturated with noise causedby the HIFU from the therapeutic transducer.

[0053]FIG. 1A illustrates an ultrasound image 10 in which a scannedfield 12 is completely obscured by noise 14, caused by the simultaneousoperation of an imaging pulse and a HIFU wave (neither shown). Inultrasound image 10, a clinician may desire to focus the HIFU wave on atreatment site 18. However, because noise 14 completely saturatesscanned field 12, it is impossible to accurately focus the HIFU waveonto treatment site 18. If the therapy transducer is completelyde-energized, noise 14 is eliminated from the scanned field. However,under these conditions, the focal point of the HIFU wave will not beseen, and thus, the HIFU wave cannot be accurately focused on treatmentsite 18. While some change in echogenicity at the HIFU focal point willpersist for a time even after the HIFU wave is gone, any change in aposition of the therapy transducer (or treatment site 18), would notregister until the therapeutic transducer is re-energized, thus the HIFUwave is cannot be focused in real time.

[0054] Some prior art systems have included a targeting icon in anultrasound image to indicate where the known focal point of a specificHIFU transducer would be located in a scanned image. While this icon maybe helpful in determining whether the HIFU was previously focused, itstill did not enable a clinician to observe real-time results. Once theHIFU therapeutic transducer was energized, the scanned ultrasound imagewas completely saturated with noise and the clinician could not monitorthe progress of the treatment without again de-energizing the HIFUtherapeutic transducer.

[0055]FIG. 1B illustrates one technique in which the amount of noisedisrupting the ultrasound image is reduced. In FIG. 1B, the HIFU wavegenerated by the therapeutic transducer has been pulsed. This techniqueproduces an ultrasound image 20, in which the location of noise 24 in ascanned field 22 is a function of the interference between the pulsedHIFU wave generated by the therapy transducer and the ultrasonic imagingpulses generated by the scanning transducer. In FIG. 1B, noise 24substantially masks a treatment site 28. This result would not occur inall cases, as to an observer noise 24 would move across scanned filed 22as the interference between the HIFU waves and the imaging pulses variedin time. Pulsing of the HIFU wave alone would thus allow the clinicianto view a noise-free image of the treatment site only when noise 24 wasrandomly shifted to a different part of scanned field 22, away from thetreatment site. However, such pulsing alone generates an image that isextremely distracting to a clinician, as noise 24 flickers acrossscanned field 22, making it difficult to concentrate and difficult toconsistently determine where the focal point of the HIFU wave isrelative to the treatment site, in real time.

[0056]FIG. 1C illustrates an ultrasound image 30 in which a HIFU wavefrom a therapy transducer has been both pulsed and synchronized withrespect to the ultrasonic imaging pulses from an imaging transducer, toensure that noise 34 does not obscure a treatment site 38. In ultrasoundimage 30 noise 34 has been shifted to a location within a scanned field32 that is spaced apart from treatment site 38, by selectively adjustingboth the pulsing and the synchronization of the HIFU wave. Preferably,noise 34 is shifted completely away from treatment site 38, thusallowing the clinician a noise-free stable image of treatment site 38that clearly shows the location of the focal point of the HIFU waverelative to the treatment site. Thus, the HIFU wave can be focused inreal time onto treatment site 38, and a clinician can, in real time,view the therapeutic effects of the HIFU wave on treatment site 38. Itwill be apparent that a clinician can de-energize the therapeutictransducer, thereby ceasing the generation of the HIFU wave, as soon asa desired therapeutic effect has been achieved at the treatment site. Inthis manner, undesired effects on non target tissue can be minimized.

[0057] The terms “therapeutic transducer,” “HIFU transducer,” and “highintensity transducer,” as used herein and in the claims that follow allrefer to a transducer that is capable of being energized to produceultrasonic waves that are much more energetic than the ultrasonic pulsesproduced by an imaging transducer, and which can be focused or directedonto a discrete location, such as a treatment site in a target area.However, not all ultrasonic waves produced by such a transducer are at ahigh intensity in at least one embodiment of the present invention, aswill be explained below.

[0058]FIG. 2 illustrates a block diagram of an embodiment of the presentinvention that synchronizes the image and HIFU waves required for thesimultaneous imaging and therapy in real time. An ultrasound imagingmachine 40 is an ultrasound imaging system of the type that is wellknown to those of ordinary skill in the art and can be purchased fromvendors such as ATL Inc., of Bothell, Wash. An imaging probe 44 that isalso of a type well known to those of ordinary skill in the art isconnected to ultrasound imaging machine 40 via a cable 42. Imaging probe44 generates ultrasonic imaging pulses that propagate to the targetarea, are reflected from structure and tissue within the body, and arereceived by the imaging probe. The signal produced by the imaging probein response to the reflected ultrasound waves is communicated to theultrasound imaging machine through cable 42 and processed to provide avisual representation of the structure and tissue that reflected theultrasonic imaging pulses. An imaging beam sector 46 from imaging probe44 is identified in the Figure by dash lines. Also included in thepresent invention is a therapeutic transducer 60. When excited, thistherapeutic transducer generates HIFU waves that are focused at aparticular point of interest, i.e., a treatment site within a patient'sbody. In FIG. 2, the path of a HIFU beam 62 is indicated by dottedlines. HIFU beam 62 narrows to a focal point 64. Those of ordinary skillin the art will recognize that position of focal point 64 relative totherapeutic transducer 60 is a function of the geometry of thetherapeutic transducer and will normally depend upon the application.For example, a therapeutic transducer that will be used to apply HIFUtherapy to the uterus of a patient from within the vaginal canal (seeFIG. 6) will have a different optimum focal point than a therapeutictransducer used to apply treatment to the uterus from outside apatient's body (see FIG. 5).

[0059] It should be noted that ultrasound imaging machine 40 differsfrom prior art systems in several ways, including its inclusion of asynchronization output signal 48. Preferably, ultrasound imaging machine40 is modified to enable synchronization output signal 48 to beobtained. Because such a synchronization output signal has not beenrequired for prior art ultrasonic imaging applications, provision of asynchronization output signal has generally not been made in prior artultrasound imaging machines. If a prior art imaging machine that has notbeen modified to provide synchronization output signal 48 is used, thesynchronization output signal can instead be derived from the ultrasonicimaging signal conveyed by cable 42.

[0060] Synchronization output signal 48 is supplied to a synchronizationdelay circuit 50. Synchronization delay circuit 50 enables the user toselectively vary the initiation of each HIFU wave with respect to eachsequence of ultrasonic imaging pulses that are generated to form anultrasonic image. Referring to FIG. 1C, delay 50 enables a user to varythe position of noise 34 in scanned field 32, so that the noise is movedaway from treatment site 38, to a different portion of scanned field 32.The user is thus provided a noise-free image of treatment site 38.

[0061] A HIFU duration circuit 52 is used to control the duration of theHIFU wave. A longer duration HIFU wave will apply more energy to thetreatment site. Generally, the more energy that is applied to atreatment site, the faster a desired therapeutic effect will beachieved. However, it should be noted that if the HIFU wave is too long,the duration of noise 34 as shown in ultrasound image 30 will increaseand can extend into the next ultrasound imaging pulse to obscuretreatment site 28, or may completely obscure ultrasound image 30,generating a display very similar to ultrasound image 10 in FIG. 1A.Thus, the user will have to selectively adjust HIFU duration circuit 52to obtain a noise-free image of treatment site 38, while providing asufficient level of energy to the treatment site to effect the desiredtherapeutic effect in an acceptable time.

[0062] A HIFU excitation frequency generator 56 is used to generate thedesired frequency for the HIFU wave, and a power amplifier 58 is used toamplify the signal produced by the HIFU excitation frequency generatorto achieve the desired energy level of the HIFU wave; power amplifier 58is thus adjustable to obtain a desired energy level for the HIFU wave.Optionally, a stable synchronization signal generator 66 can be used tosynchronize the HIFU wave to the imaging ultrasonic wave, instead ofusing synchronization output signal 48 from ultrasound imaging machine40. Stable synchronization signal generator 66 can be used to provide astable synchronizing pulse to initiate the HIFU wave, and the timing ofthis stable synchronizing pulse can be selectively varied until anoise-free image of the treatment site has been obtained. A drawback ofusing stable synchronization signal generator 66 instead ofsynchronization output signal 48 is that any change in the timing of theultrasound imaging pulses, such as is required to scan deeper withintissue, will require an adjustment to stable synchronization signalgenerator 66 that would not be required if synchronization output signal48 were used. The processor will be able to automatically find a stablesynchronization signal using information from the movement of the noise.

[0063] FIGS. 3A(1)-3D(4) and FIG. 4 provide further detail for thesynchronization and pulsing features of the present invention. FIG.3A(1) shows ultrasound imaging pulses 46 a produced by imaging machine40 and imaging probe 44 that are used to acquire an ultrasound image ofa target area (such as ultrasound image 30 of FIG. 1C). Asynchronization pulse 48 a is shown in FIG. 3A(2). It should be notedthat synchronization pulse 48 a is illustrated as occurring before thegeneration of ultrasound imaging pulses 46 a; however, the timing ofsynchronization pulse 48 a relative to the imaging pulses is notcritical, so long as it is stable. Synchronization pulse 48 a merelyestablishes a timing reference point, from which a delay 50 a (shown inFIG. 3A(3)), used for the initiation of the HIFU wave, is set such thatnoise from the HIFU wave in an ultrasonic image generated by imagingpulses 46 a is shifted away from the image of the treatment site. Thedelay 50 a is not fixed, and it is adjusted by the user until anoise-free image of the treatment site is obtained.

[0064] A HIFU duration 52 a, shown in FIG. 3A(4), determines theduration of the HIFU wave. HIFU duration 52 a may be very brief, asshown in FIG. 3A(4), or extended, as shown in FIGS. 3B(4) and 3C(4). Anincrease in the duration of the HIFU wave will cause a greater portionof an ultrasound image to be obscured by noise, and may cause the HIFUwave to interfere with the image of the treatment site. In FIG. 3A(4),delay 52 a is very short, and the resulting noisy region in theultrasound image will be very small. However, a short duration HIFU wavemeans a correspondingly small amount of HIFU energy will be delivered tothe treatment site, thus increasing the length of the treatment. Aclinician must balance the length of HIFU duration needed to maintain anoise-free image of the treatment site against the time required tocomplete the therapy. It should be noted that as an alternative to usingHIFU duration 52 a to control the HIFU excitation frequency generator tovariably set the duration of the HIFU wave, the HIFU excitationfrequency generator itself could be adjusted to control the duration.

[0065] FIGS. 3B(1)-3C(4) similarly illustrate timing patterns thatincorporate different settings for the delay relating to the initiationof the HIFU wave (setting 50 b in FIG. 3B(2), and setting 50 c in FIG.3C(2)) and delay relating to the duration of the HIFU wave (setting 52 bin FIG. 3B(3), and setting 52 c in FIG. 3C(3)). FIGS. 3D(1)-3D(4)illustrate a timing pattern that enables a longer duration HIFU wave(thus more energy applied to the treatment site) to be used, while stillenabling a noise-free image of the treatment site to be generated. InFIG. 3D(1), ultrasound imaging pulses 46 b and 46 c appear to be muchshorter than in FIGS. 3A(1), 3B(1) and 3C(1), but actually are of thesame duration, as the scales of FIGS. 3D(1)-3D(4) have beensignificantly increased. Synchronization pulse 48 a of FIG. 3D(2) isobtained and used as described above. A delay 50 d in FIG. 3D(3) is setto obtain a noise-free image of the treatment site, also as describedabove; however, as will be clarified below, not all of thesesynchronization pulses govern the image that is produced, as the delay52 d dominates. The significant difference between FIGS. 3D(1)-3D(4) andFIGS. 3A(1)-3C(4) is that delay 52 d has been significantly increased inFIG. 3D, such that a very long burst of HIFU energy is emitted, almostto the point of continuous emission. Here, the noise-free imaging occursonly every seventh image, during interrogation wave 46 c. By adjustingdelay 52, more or fewer images will be interfered with, and therefore,various duty cycle lengths for HIFU exposure can be accommodated. Itshould be noted as the number of images interfered with by the HIFU waveincreases (here, 6 out of 7), the resulting image of the target areawill arguably provide less real-time feedback. However, the actual timebetween visible images of the treatment site may be so short as toappear to occur in real time. But, at very high settings for the HIFUduration (such as to cause the HIFU wave to interfere with 99 out of 100images of the treatment site), the advantages associated with real-timeimaging of the treatment site are diminished. Thus, the HIFU durationwill preferably not be set so high as to negate the benefits ofreal-time imaging of the treatment site and its ability to provide theclinician with immediate feedback concerning the effect of the therapyon the treatment site.

[0066]FIG. 4 illustrates another timing sequence that shows therelationships between ultrasound imaging pulses 46 d, a synchronizationpulse 48 b, a delay 50 e, and a HIFU duration 52 e. In this timingsequence, synchronization pulse 48 b occurs during the ultrasoundimaging pulses 46 d, rather than preceding the ultrasound imagingpulses, as shown in FIGS. 3A-3D. As noted above, the position of eachsynchronization pulse 48 b relative to the ultrasound imaging pulses isnot critical, as delay 50 e is adjusted to shift the noise away from theimage of the treatment sight. Again, the duration of the HIFU wave (andthus, the energy applied to the treatment sight) is varied either byadjusting delay 52 e, as shown in FIG. 4, or by adjusting the HIFUexcitation generator.

[0067] Imaging of HIFU Focal Point

[0068] It will often be important for a clinician to be able to confirmthat the focal point of a HIFU transducer is directed at a desiredtreatment site before initiating HIFU therapy. It has been determinedthat if the energy level of a HIFU transducer is reduced to a level lessthan a level that would cause any damage to tissue, the focal point ofthe HIFU transducer will still be evident within the target areadisplayed in the image developed from the reflected ultrasound signalproduced and received by the ultrasound imaging transducer. The focalpoint will appear as a bright spot in the displayed image and willrapidly fade over time. Thus, it is possible for a clinician to move theHIFU transducer as necessary to shift the focal point to a desiredtreatment site in the target area being imaged by the ultrasound imagingtransducer and to see the focal point in the image as a bright spot thatmoves as the position of the HIFU transducer is changed. Only after thefocal point is positioned on a desired treatment site will the clinicianincrease the energy of the ultrasound pulses produced by the HIFUtransducer to a level sufficient to achieve the desired therapeuticeffect, e.g., to a level sufficient to necrose tissue, or causehemostasis. It should be noted that the ultrasound imaging transducer isnot receiving the ultrasound signal produced by the HIFU transducer thatis reflected by the tissue, but instead, is likely imaging the effect ofthe change in echogenicity of the tissue caused by the relatively lowenergy ultrasound burst produced by the HIFU transducer. This techniquecan be used with any of the HIFU transducers discussed below.

[0069] A further advantage of the preceding technique for imaging thefocal point of a HIFU transducer can be achieved by storing the image ofeach successive treatment site, which will appear as a bright area inthe image produced by the ultrasound imaging transducer system. Forexample, a storage type display, of the type readily available, can beused for this purpose. By storing the image of each treatment site towhich the HIFU therapy has previously been administered during a currentsession, it is possible for a clinician to target spaced-apart treatmentsites in the target area, thereby ensuring the HIFU therapy has beenadministered to all of the desired portion of a tumor or other structurein the patient's body. Since each previous treatment site will bevisible in the image, it will be apparent that a desired pattern oftreatment sites can readily be laid down over the tumor or otherstructure of interest. The change in echogenicity caused by a relativelyhigh energy therapeutic HIFU wave will be brighter and persist longer inthe display, enabling the clinician to easily distinguish between acurrent prospective focus point for the next treatment site (producedusing the low energy pulse) and the previous treatment sites to whichthe HIFU therapy has already been administered.

[0070] 3D Imaging System

[0071] In FIG. 22, a block diagram is illustrated for a system 200 thatenables imaging of a target area in 3D and storing of the locations oftreatment sites to which the HIFU therapy has been administered in the3D image as a HIFU therapy session proceeds. The system includes a 3Dimage data processor and display 202, an image acquisition section 204,a magnetic field sensor 206, a magnetic field generator 208, and 6Delectronic processing circuitry 210. The latter three components areemployed to track the imaging target area and the HIFU focal point asthey are redirected in the 3D space and are part of a six-dimensional(6D) measurement system (i.e., three spatial coordinates for the 3Dorthogonal axes and three angles of rotation around these threeorthogonal axes). A 6D measurement system is commercially available fromAscension Technology, Burlington, Vt. This 6D measurement system uses 6Delectronic processing circuitry 210 and magnetic field generator 206 toproduce time sequential orthogonally oriented magnetic fields covering ageneral area as indicated in the Figure by the dash line thatencompasses the region of magnetic field. Magnetic field sensor 206 ismounted on a combined imaging and HIFU therapy probe 212 in a fixedmanner relative to imaging and HIFU transducers 214. The magnetic fieldsensor detects the magnetic field strength in 3D sequentially producedby the magnetic field generator. The 6D electronic processing circuitryuses the information from the magnetic field sensor and the knownmagnetic fields that were produced to compute the 3D position and thethree angular orientations around the three orthogonal axes of themagnetic field sensor (and thus, of the combined imaging and HIFUtherapy probe) with respect to the magnetic field generator, yieldingthe 6D information. The 6D information is supplied to 3D image dataprocessor and display 202 at a rate sufficient to enable movement of themagnetic field sensor to be tracked in the displayed 3D image of thetarget area. With information derived from calibrating system 200 withthe imaging probe, the position of the target area and the HIFUtransducer focal point can be related to a 3D spatial point, so long asmagnetic field sensor 206 is within the range of the magnetic fieldproduced by magnetic field generator 208. 3D image data processor anddisplay 202 also receive ultrasound image information from an ultrasoundimaging machine 216 through image acquisition section 204. It uses thisinformation to develop and display 3D information. Ultrasound imagingmachine 216 provide the synchronization signal to a HIFU control andelectrical energy generating system 218, as discussed above. Theremaining component in FIG. 22 is a physiological informationacquisition section 220, which enables synchronization of the imagingand HIFU therapy with physiological activity, such as respiration orcardiac activity (provided by an electrocardiogram system—not shown).Use of the physiological information avoids problems associated withmovement of the patient's body due to physiological activity. Forexample, 3D imaging and HIFU therapy can be control so that they areimplemented only at the end of expiration in the breathing cycle, sincemotion of the patient is more repeatable then than at mid inspiration. Aphysiological sensor such as a respiration detector (not shown), whichis well known in the art, can provide the information for this sectionof the system.

[0072] As noted above, by storing the location of each of the treatmentsites where HIFU therapy has been administered during a therapy session,a clinician will be able to determine where each successive treatmentsite should be targeted to achieve a desired pattern of HIFU therapywithin a tumor or other region of interest. The bright spot in the 3Dimage showing the location of each previous treatment site greatlyfacilitates this targeting process and enables a desired pattern of HIFUtherapy to be achieved with considerable accuracy.

[0073] By using the 3D display to view the progression of successivetreatment sites, other types of therapeutic results can be achieved. Forexample, the HIFU therapy can be employed to create a plurality oflesions on blood vessels supplying blood to a tumor, cutting off thesupply of nutrients and oxygen to the tumor provided by the bloodsupply. Thus, it is possible to destroy a tumor without directly usingthe HIFU therapy to destroy tumor tissue. The results of this techniqueare similar to those arising from the procedure referred to as“embolization,” in which a clot-inducing material is introduced into thevessel using a small catheter, but the HIFU therapy can achieve the sameresult non-invasively and can treat vessels that are too small orotherwise not accessible to render treatment through a catheter.Embolization is a relatively new technique and has been used to treat avariety of conditions, including uterine fibroids. While the ability tostore the location of previous treatment sites so that they are shown ona displayed 3D image of the target area is not essential to this use ofHIFU therapy, it will be evident that the display of the treatment sitesused to create lesions in the vessels will facilitate this procedure. .Further, it should be noted that using HIFU to occlude (or inducehemostasis in) the blood vessels that supply oxygen and nourishment to astructure within the body can be used in conjunction with other imagingtechniques, such as CT, MRI, or angiography.

[0074] Another imaging technique that is likely to be useful to aclinician when using HIFU to create lesions in blood vessels is DopplerFlow imaging, which can be used to represent blood vessels supplying astructure with blood in one color, and blood vessels that remove bloodfrom a structure in a second color. As those of ordinary skill in theart will readily recognize, the circulation of blood within these bloodvessels either adds to or subtracts from the imaging wave, enablingblood vessels having blood flowing in opposite directions to bedifferentiated from one another.

[0075] A final imaging technique that will likely be beneficiallyemployed by a clinician using HIFU to create a lesion in a blood vesselis the use of conventional ultrasound imaging contrast agents. Not onlywill the use of such agents provide the clinician with a more usefulultrasonic image, but it is anticipated that such agents may actuallyincrease the effectiveness of the HIFU in producing the desired lesion.

[0076] Use of Anesthetic Agent to Enhance Image of Low Power HIFU at aTreatment Site

[0077] While operating a HIFU transducer at a substantially reducedpower to determine the location of its focal point within a target areawill produce a bright spot visible in the image, it may sometimes bedesirable to enhance the visibility of the focal point in the image—ineither a 2D or 3D image. The change in echogenicity of the tissue due tothe administration of a relatively low power HIFU wave to the tissue iswhat enables the location to be seen in the image of the target area.However, it is believed that a substantially brighter spot showing wherethe HIFU wave (at low power) was focused can be achieved if ananesthetic agent other blood soluble agent having a relatively highvapor pressure has previously been administered to the patient. Use ofsuch agents, which will readily vaporize when exposed to the slightelevated temperatures caused by low power ultrasound on tissue, shouldproduce small bubbles at the focal point of the HIFU transducer. Thesebubbles will produce a substantially brighter spot in the ultrasoundimage and at an even lower energy level of the HIFU transducer than thespots produced by the low energy HIFU waves when no such agent has beenadministered to the patient. Reduction of the HIFU energy to an evenlower level will further ensure that the focal point of the HIFUtransducer can be seen in the ultrasound image produced by the imagingtransducer without risk of damage to tissue that is not to be treated.

[0078] Advantage of Simultaneous, Real-Time Imaging

[0079] Major advantages to real-time imaging of therapeutic HIFU whileit is being applied are: (1) the HIFU treatment can be stopped when atherapeutic produced lesion has grown to the point at which it begins toextend beyond the desired treatment site, and the HIFU focal point canthen be repositioned to another treatment site and reactivated; (2) thefocal point of the HIFU wave can be observed in the image due to changesin the echogenicity of the tissue at the focal point, which are apparentin the images of the target area, providing an instant feedback that canenable a clinician to adjust the focal point onto a desired treatmentsite; (3) the HIFU focal point can be adjusted during the administrationof the HIFU therapy to compensate for tissue movement within thepatient's body due to breathing or for other reasons; (4) real-timevisualization of a treatment site is very reassuring to the medicaltherapist, in confirming that the HIFU energy is being applied to thecorrect position (and that healthy tissue is not being damaged); (5) thecombined imaging and therapeutic treatment can be accomplished muchfaster than in the past, when it was necessary to render treatment, stopthe treatment, image the site, and then continue the treatment; and, (6)it enables the clinician to administer the HIFU therapy in a desiredpattern of treatment sites so that, for example, a matrix of necroticpoints in a tumor can be achieved to de-bulk the tumor without treatingall of the tumor. Further details of how each of these advantages areachieved by the present invention are discussed below.

[0080] FIGS. 5-7 illustrate how a variety of different configurations ofHIFU transducers and imaging transducers can be used to simultaneouslyprovide real-time imaging and therapy to an internal treatment sitewithin a patient's body. It is expected that HIFU therapy with real-timeimaging can be beneficially employed to treat a variety of diseaseconditions. In particular, it is envisioned that conditions relating tothe reproductive system of a mammalian female will particularly benefitfrom HIFU therapy with real-time imaging, as ultrasonic imaging itselfis widely used in association with the female reproductive system. It isenvisioned that HIFU therapy can be applied to a uterine fibroid, anendometrial polyp, a follicular cyst, a polycystic ovary, a dermoidcyst, a corpus luteum cyst, an ectopic pregnancy, a cornual pregnancy, amultifetal pregnancy, a uterine malformation, an endometrialhyperplasia, an adenomyosis condition, and endometriosis condition, oran excessive bleeding condition. The treatment of disorders of thefemale reproductive system using the method of the present invention canbe achieved by positioning the scanning ultrasonic transducer system andthe therapeutic ultrasonic transducer system adjacent to the femalereproductive system. Vaginal, rectal, abdominal and laparoscopicapproaches are contemplated.

[0081] In FIG. 5, both a HIFU transducer 102 and an imaging transducer104 are disposed external to the patient's body. The reflectedultrasound waves received by imaging transducer 104 are used to generatean ultrasound image 100. In FIG. 5, the HIFU is being used to treat atumor 110 on a uterus 111 of the patient. Imaging transducer 104 ispositioned so that tumor 110 is clearly displayed in ultrasound image100. Also visible in ultrasound image 100 is a cross section of a rectum106. HIFU transducer 102 is being used to destroy tissue in tumor 110.The necrotic tissue is clearly visible as a lesion 112 in both the crosssection of the body and in ultrasound image 100.

[0082]FIG. 6 illustrates an embodiment in which a HIFU transducer 102 aand an imaging transducer 104 a have been combined on a vaginal probe109. Vaginal probe 109 has been inserted into a vaginal canal 108 a andpositioned to enable imaging transducer 104 a to be used in generatingan ultrasonic image of a tumor 110 a. Once tumor 110 a has been located,HIFU transducer 102 a is focused on a selected portion of tumor 110 a towhich the clinician desires to administer the HIFU therapy to generate alesion 112 a. The HIU therapy is used to destroy the tumor by causinglesions of the blood vessels supplying oxygen and nutrients to thetumor, thereby generating a plurality of lesions similar to lesion 112a, so that the tumor withers away, or by destroying spaced-apartportions of the tumor. Particularly if the latter technique is used, theHIFU therapy will likely be repeated at intervals of several weeks. Thetime between successive therapy sessions enables macrophages in thepatient's body to clear away or debride the necrotic tissue from thetumor so that it is reduced in size with each therapy session andeventually destroyed.

[0083]FIG. 7 illustrates a rectal probe 109 a, which incorporates acombination of a therapy transducer 102 b and an imaging transducer 104b. Rectal probe 109 a has been inserted into a rectum 106 b of thepatient, and the imaging transducer is being used to locate a tumor 110b. Once tumor 110 b has been located, therapy transducer 102 b isfocused on the desired portion of the tumor, and HIFU therapy isadministered to a treatment site 112 b, until the desired therapeuticeffect is achieved.

[0084] FIGS. 9-19 provide details of preferred embodiments of probesthat can be used to simultaneously provide imaging and therapy to atreatment site. It should be noted that the method of simultaneouslyimaging and providing treatment using ultrasound can be applied todifferent locations in or on a patient's body to treat a variety ofmedical conditions. One application of a preferred embodiment of thepresent invention is employed, by way of example, to providedsimultaneous ultrasonic imaging and HIFU therapy of a uterine fibroid.However, it should be understood that the simultaneous imaging andtherapy using the described method is not at all limited to thetreatment of uterine fibroids, or even the treatment of gynecological orobstetrical disorders.

[0085] For an exemplary application of the present invention describedbelow, a vaginal ultrasonic imaging probe is employed. Vaginalultrasonic imaging probes are well known in the prior art. FIG. 8illustrates one such prior art ultrasonic vaginal imaging probe, whichis a Model C9-5 transvaginal probe available from ATL Inc. of Bothell,Wash. It is envisioned that several different types of HIFU transducerscan be mounted onto the standard transvaginal imaging transducer probeto allow the simultaneous imaging and therapy of treatment sites relatedto the female reproductive system, in accord with the present invention.

[0086] Transducer and Probe Design for the Vaginal Application of HIFUto Treat Uterine Fibroids

[0087] As noted above, an exemplary application of the present inventionis a vaginal probe incorporating both imaging and therapeutictransducers. As HIFU transducer design is a function of the location ofthe desired treatment site, the following discussion is useful indetermining preferred design parameters for a vaginal probe combiningimaging and therapeutic transducers optimized for applying HIFU therapyto uterine fibroids.

[0088] The relationship between the distance from the HIFU transducer tothe focus (focal length) and the surface area of the aperture is wellknown to those of ordinary skill in the art. For a circular aperture,the j# (or relative aperture) is defined as being equal to the “focallength divided by the diameter of the aperture”. A low number ispreferred, as this insures a highly focused beam, thereby minimizing anyundesired effects of the HIFU beam on adjacent tissue. A preferrednumber is 1; but a number as high as 1.75 can be used, therefore apractical range is from 1-1.75. The lower the number, the tighter thefocus, and the greater the intensity of the HIFU beam will be at thefocus, with respect to the HIFU beam intensity at the surface of thetransducer. This is important because a high intensity is required atthe focal point to achieve a desired therapeutic effect in a shortperiod of time. Conversely, moderate or low intensities are needed atthe surface of the transducer, so that the HIFU beam generated at thesurface of the transducer can pass through the tissue intermediate tothe transducer surface and the focal point. This intermediate tissue isaffected by the at this point unfocused HIFU beam as it passes throughthe intermediate tissue to the focal point. If the unfocused HIFU beamis of sufficiently low intensity, the effect of the unfocused HIFU beamon the intermediate tissue will be negligible. As the unfocused HIFUbeam approaches the focal point, the intensity increases as the HIFUbeam becomes more focused, until a sufficient intensity is obtained atthe focal point to achieve a desired therapeutic effect. Generally, theeffect a HIFU beam has on tissue is to heat the tissue (though HIFU canalso have a mechanical effect on tissue via cavitation). Therefore a lowintensity at the surface of the transducer is desired to minimize theheating of the intermediate tissue, while for successful treatment, thetissue at the focus must be heated much more rapidly in order to achievetherapeutic temperatures at the focus without undue heat build up in theintermediate tissue. Therefore, it is very important to know the maximumdistance from the transducer that one desires to treat, to determine themaximum focal length required. At the same time, one must have anunderstanding of the largest size aperture that one can physicallyintroduce into the vaginal tract.

[0089] Based on a review of obstetrical and gynecological literature,the applicants experience, and a study of duckbill speculums (medicaldevices used for the inspection of the vagina and cervix.), applicantshave identified that the external opening of the vaginal canal generallyhas a circumferential dimension which ranges from of 10-12 cm. Since thevaginal entrance is longitudinal in nature, a probe having a distal endthat is “paddle” or “spoon” shaped would be most beneficially employed.Practical transducer considerations require that the distal end of theprobe (the logical point for mounting a therapeutic transducer) would beat least 0.5 cm thick, and that the widest portion of this “paddle”design would range from 4.5-5.5 cm. Since the vagina is a muscularstructure that is quite strong, it can be stretched somewhat further,but this is uncomfortable for the patient. Therefore, it is preferredthat the widest portion of the paddle range from 4.5-6 cm.

[0090] The design of a preferred focal length necessitated an analysisof where within the vaginal canal the probe will be positioned, andwhere uterine fibroids are likely to occur. Preferably the probe will bepositionable in the vagina at the cervix. The vaginal fornices arepotential spaces formed by folds within the vaginal canal around thecervix, extending 5-6 cm along the uterus. Therefore, near the cervix,the vaginal cavity has a larger space, allowing either a larger probe,or the manipulation of a smaller probe, to achieve imaging and therapyof a desired site in the uterus. Based on a review of obstetrical andgynecological literature, the size range of uterine fibroids is from1-15 cm, and the length of the uterus is approximately 5-6 cm.Therefore, a maximum focal length of about 20 cm would reach an entirefibroid located at the distal end of the uterus. Based on applicants'practical experience, it is anticipated that 20%, 35%, 50%, 75%, and 80%of all uterine fibroids will be within the respective distances of 4 cm,6 cm, 8 cm, 10 cm and 12 cm respectively. From a cost/benefit point ofview, a combination imaging and therapeutic vaginal probe needs to beable to treat at least 35% of uterine fibroids, and more preferably 50%.Therefore a preferred therapeutic transducer must be able to treat to adepth of at least 6 cm, and more preferably 8 cm.

[0091] The design of different embodiments of a vaginal probe includingboth imaging and therapeutic transducers is preferably limited todesigns in which the largest circumferential dimension of thecombination probe (measured generally transverse to a longitudinal axisof the probe) is about 10.6 cm, which is a nominal limit in size toenable the combination imaging and therapy transducer to be readilyinserted through the vaginal opening and into the vaginal canal. TABLE 1Percentage of Fibroids Treatable for Relative Apertures with an areaequivalent to a Circular Aperture Circular Aperture Relative Apertures(f #) Diameter (cm) 1.25 1.5 1.75 4.5 <35% >35%  50% 5  35% <50% <75%5.5 <50%  50% <75% 6 <50% <75%  75% 6.5  50% <75% <80% 7 <75%  75%  80%7.5 <75% <80% 8 <75%  80% 8.5  75% 9 <80% 9.5  80%

[0092] Based on the calculations for a circular aperture and practicalrelative apertures, Table 1 provides information of the relativepercentages of uterine fibroids that can be treated with a specificcircular aperture. For a circular aperture of 4.5 cm, just less than 35%of all uterine fibroids can be treated with a relative aperture of 1.25.This then defines the minimum diameter of circular applicator as 4.5 cm,based on the design parameter of being able to treat 35% of uterinefibroids encountered. An elliptic aperture may also be used, in whichcase the minor axis represents the transverse direction, and thus thelimiting dimension of a probe that can readily be inserted into thevagina. An elliptical surface area is larger than a circular surface ifthe minor axis length equals the diameter of the circular surface, andthe major axis is greater than the minor axis. By using an ellipticalsurface, the focal length is greater than for a circular surface for agiven relative aperture number. Therefore, with a two to one ratio ofmajor to minor axis for example, a 9/4.5 ratio would exist for the minoraxis chosen. Referring to Table 2, this is equivalent to a 6.5 cmdiameter circular aperture. Looking at Table 1, for the equivalent of a6.5 cm diameter circular aperture, the percentage of fibroids that canbe treated are 50%, <75% , and 75%, respectively, for relative aperturesof 1.25, 1.5, and 1.75.

[0093] These results therefore dictate a vaginal probe with a HIFUtransducer that has a distal end that is paddle or spoon shaped, with aminimum transverse dimension of 4.5 cm, and a maximum circumferentialdimension (measured generally transverse to a longitudinal axis of theprobe) of about 10.6 cm. No other devices cited in the prior art for usein other body orifices are suitable for a vaginal application of HIFUfor the treatment of uterine fibroids. The size, shape, andconfiguration of such a combination imaging and therapy vaginal probeare believed to be specific to this particular access path through thevaginal canal, for rendering the HIFU therapy in treating obstetricaland gynecological medical conditions. TABLE 2 Major axis length (cm) fora given a minor axis length that gives an ellipsoidal area equal to thearea of a circular aperture of a specific diameter. Diameter CircularEllipsoid Minor Axis Length (cm) Aperture 4.5 5 5.5 6 4.5 4.5 4.1 3.73.4 5 5.6 5.0 4.5 4.2 5.5 6.7 6.1 5.5 5.0 6 8.0 7.2 6.5 6.0 6.5 9.4 8.57.7 7.0 7 10.9 9.8 8.9 8.2 7.5 12.5 11.3 10.2 9.4 8 14.2 12.8 11.6 10.78.5 16.1 14.5 13.1 12.0 9 18.0 16.2 14.7 13.5 9.5 20.1 18.1 16.4 15.0

[0094]FIG. 9 illustrates a first embodiment for mounting a HIFU module123 onto a distal end of a prior art transvaginal imaging probe 120.Transvaginal imaging probe 120 includes an imaging transducer array 122.HIFU module 123 is sized and shaped to fit over the distal end oftransvaginal imaging probe 120 and incorporates a cylindrical shaft 124that has a cylindrical bore 126. Cylindrical bore 126 is sized to easilyslide over the distal end of transvaginal imaging probe 120 and in itswall is disposed a plurality of fluid passages 130. Those of ordinaryskill in the art will readily understand that ultrasonic waves do notreadily pass through air gaps, and water or other fluid filled balloonsare often used to conduct an ultrasonic wave between the ultrasonictransducer from which it is transmitted and a target of interest. Fluidpassages 130 are used to circulate degassed water through a balloon 140(FIG. 10) that surrounds HIFU module 123. It is important that the waterbe degassed, as bubbles within the water increase cavitational effects,which will attenuate the ultrasonic waves. The water circulating throughthe balloon provides cooling to the transducer elements to avoid anunwanted buildup of heat. It is currently common practice to use acondom for a balloon, although other inert and flexible elastomericmaterials could be used.

[0095] In FIG. 10, vaginal probe 120 has been inserted into cylindricalbore 126 of cylinder 124, and the imaging transducer array 122 isdisposed within a void 138. Shaft 124 also includes electrical leads128, which connect the HIFU transducer to the power amplifier thatdrives the HIFU transducer. Located atop cylinder 124 is a HIFUtransducer mounting base 136. It should be noted that HIFU transducermounting base 136 is also hollow, such that the transvaginal imagingprobe 130 may pass completely through the center of HIFU transducermounting base 136 so that imaging transducer array 122 is disposedwithin void 138 (see FIG. 9B). This configuration enables imagingtransducer array 122 to transmit an ultrasound imaging pulse to thetarget of interest.

[0096] As shown in FIG. 10, HIFU therapy transducer 132 is pivotallymounted to HIFU transducer mounting base 136 at a pivot joint 134. Thispivotal mounting enables a clinician to selectively target a widervariety of treatment areas within the female reproductive system byrotating the HIFU transducer about pivot joint 134. It is envisionedthat the disposition of the HIFU transducer on pivotal mounting 134 willbe adjusted prior to inserting the combination transvaginal probe andHIFU module into the vaginal canal. The angle of the HIFU transducershould be adjusted based on the relative position of the target area andtreatment site. Once in the vaginal canal, the combination transvaginalimaging probe and HIFU module can be moved to a position that enables anultrasonic image of the target area to be observed on a display and thenadjusted to focus the HIFU wave onto a desired treatment site within thetarget area.

[0097] It is envisioned that a mechanical linkage (not shown) connectedto HIFU transducer 132 can be added to enable the HIFU transducer to beselectively rotated about pivot joint 134 while the combinationtransvaginal probe and HIFU module is in the vaginal canal. Thiscapability would provide a clinician greater flexibility in focusing theHIFU transducer on a particular treatment site. However, it should benoted that a skilled clinician can initially select an angle for theHIFU transducer relative to the longitudinal axis of the transvaginalimaging probe, insert the combination vaginal probe and HIFU module intothe vaginal canal, and then manipulate the combination imaging probe andHIFU module while in the vaginal canal to acquire the image of thetarget area and focus the HIFU beam on the desired treatment site.

[0098]FIG. 11 illustrates an ultrasonic image 142 superimposed on thecombination transvaginal probe and HIFU transducer illustrated in FIG.10 (but without balloon 140). In FIG. 11, the HIFU transducer 132 hasbeen focused on a treatment site 144. The synchronization and pulsatingelements described earlier have been used to shift a noise section 146away from treatment site 144, such that the clinician is provided with anoise-free real-time image of treatment site 144.

[0099]FIG. 12 illustrates another embodiment of a combination imagingand therapy transducer based on a prior art transvaginal imaging probe.A therapy transducer module 150 has been mounted onto transvaginalimaging probe 120. The design of the module is constrained by theanatomy involved in the transvaginal application of HIFU to uterinefibroids, as discussed above. Module 150 is mounted at the tip of thevaginal probe, and contains an opening through which the scan head(imaging transducer) transmits an ultrasound wave to obtain an image ofthe uterus, the fibroid, and any other structure of interest. Theopening allows about one half of the scan head to transmit the imagingultrasound wave. The other half is covered by the module assembly, anddoes not have a window for imaging, and therefore does not contribute tothe image. In other words, half of the ultrasound image obtained by thevaginal probe in this configuration is masked by the assembly and isblank. The main housing of the module is made of biocompatible, medicalgrade plastic. A chamber 158 can be filled with a fluid, such asdegassed water, for the purpose of coupling the HIFU to adjacent tissue.A water circulation system is used to circulate degassed cold waterthrough chamber 158 for both cooling of the HIFU transducer and carryingaway any cavitation bubbles that may be generated during the HIFUexcitation. The water conduits extend through the plastic housing andtwo holes disposed on opposite sides of a central passage (not shown).Stainless steel needle stock can be employed for tubes 155 carrying thewater in and out of the chamber. Tubes 155 run along the shaft of thevaginal probe adjacent to a coaxial cable 153 employed for energizingthe HIFU transducer. A cover 159 attaches the membrane which formschamber 158 to module 150.

[0100] Further details of therapy transducer module 150 are provided inFIG. 13. A HIFU transducer 154 is disposed on a rim cut inside a brassbowl 152 that is affixed with an appropriate adhesive to module 150. Anelectrical connection to the HIFU transducer is made through coaxialcable 153 that runs along the shaft of the probe. Preferably, the HIFUtransducer is a concave, fixed focused transducer, operating at a centerfrequency of about 2.0 MHz. The radius of curvature of this embodimentof the HIFU transducer is about 55 mm, and its aperture diameter isabout 35 mm. The focus of the HIFU transducer is within the imagingplane of the imaging probe (preferably an ATL, Inc., Model C9-5transvaginal probe). In fact, the imaging plane intersects the HIFU beamenvelope (cone shaped) through its center, placing both the focus andthe HIFU beam longitudinal axis in the imaging plane, as can be seen inFIG. 14.

[0101] The HIFU transducer frequency was selected based on severalrequirements, including: (1) the ability to administer HIFU therapy touterine fibroids up to a maximum distance of about 6 cm from the cervix;and, (2) an intensity gain of about 20 dB from the transducer surface tothe focal spot, providing about 1,000 W/cm² at the focus, and about 50W/cm² at the transducer surface. These are all reasonable values forboth treatment and transducer operation. Two different embodiments ofchambers containing degassed water are contemplated for the purpose ofcoupling the HIFU to adjacent tissue. These embodiments include achamber containing just the HIFU transducer, and a chamber containingboth the HIFU transducer and the imaging scan head.

[0102]FIG. 14 illustrates a combination transvaginal probe and HIFUtransducer with both the imaging and HIFU transducer energized andchamber 158 filled with fluid. The HIFU transducer produces acone-shaped HIFU wave 162 that is focused at a focal point 166. Theimaging transducer generates a scanning ultrasound wave 160. It shouldbe noted that HIFU wave 162 is within scanning wave 160. Thus, focalpoint 166 can be readily seen in the image provided by scanningultrasound wave 160.

[0103]FIG. 15 illustrates an alternative design of a therapy transducermodule 170 mounted on transvaginal imaging probe 120. As in the previousembodiment, imaging transducer array 122 is partially occluded by module170, and thus only a partial ultrasound image is generated. A HIFUtherapy transducer 174 is mounted on a brass ring 178, in a mannersimilar to the configuration in the previous embodiment. A fluid filledchamber 158 a encloses HIFU therapy transducer 174. The most significantdifference between the embodiment illustrated in FIG. 15 and theembodiments illustrated in FIGS. 13 and 14 is that fluid filled chamber158 a of FIG. 15 only encloses HIFU therapy transducer 174, and notimaging transducer array 122 as well.

[0104]FIGS. 16 and 17 illustrate an embodiment of probe usable in thepresent invention in which the HIFU therapy transducer and imagingtransducer have been integrated into a single device. It is anticipatedthat as the combination of real-time imaging and HIFU therapy gainsacceptance, clinicians will desire an integrated device rather than aHIFU transducer and a imaging transducer configured as two separatecomponents, mounted together on a single probe. An integrated imagingtransducer and a therapy transducer are formed as a combinationtransvaginal probe 180 as shown in these Figures. FIG. 17 illustratesthat the angle of a paddle head 186 containing both the therapy andimaging transducers is movable relative to the body of combinationtransvaginal probe 180. As was discussed in regard to the firstembodiment of the transducer module that included the pivoting HIFUtransducer, it is expected that paddle head 186 will be placed in adesired position prior to placing combination transvaginal probe 180into a patient's vaginal canal. However, it is again envisioned that alinkage mechanism can be incorporated that will enable paddle head 186to be moved relative to the handle portion of combination transvaginalprobe 180, while the paddle head is disposed in the vaginal canal. Asnoted earlier, the paddle head configuration is particularly well suitedfor use in the vaginal canal.

[0105]FIGS. 18 and 19 illustrates the paddle head probe with imagingtransducers 182 and 182 a positioned at two different angles relative tothe longitudinal axis of the paddle head. In FIG. 18, imaging transducer182 is generally parallel to the axis, while in FIG. 19, an imagingtransducer 182 a forms an angle of 90° relative to the axis. Those ofordinary skill in the art will recognize that the spatial orientation ofthe imaging transducer determines the plane of the scanning field. Itshould be noted that imaging transducers 182 and 182 a comprise aone-dimensional (1D) phased array of transducer elements, and a lineararray concentric ring HIFU transducer 184 is provided. Those of ordinaryskill in the art will readily understand that the 1D phased arrayimaging transducers allow the ultrasound waves that are generatedthereby to be steered and focused through a substantial range in aplane, while the concentric phased array of the HIFU transducer can onlybe electronically focused at different points along its central axis.The probe can thus remain stationary while the scanning ultrasonic waveare steered and/or focused at a target area and the HIFU waves arefocused on a treatment site within the target area.

[0106] Also shown in FIG. 19 is a vibrating element 190. When activated,vibrating element 190 causes the focal point of the therapeuticultrasonic wave to be varied, thus enlarging the size of the treatedarea within a limited portion of the target area without requiring theclinician to move the probe. Preferably, the clinician can select fromtwo vibrational patterns; a first pattern that involves a vibrationalfrequency in the range of 1 to 5 Hz (thereby avoiding the heating oftissue not associated with the treatment site), and a second patternthat involves a vibrational frequency in the range of 10 to 50 Hz(thereby increasing an amount of energy applied to the treatment site,while avoiding undesired cavitational effects). While a specific type ofvibrating element is not required, it is envisioned that readilyavailable electromechanical vibrating elements will be employed for thispurpose. It should be noted that vibrating element 190 could bebeneficially incorporated into other probe embodiments as well, and isnot limited to only the embodiment illustrated in FIG. 19.

[0107]FIG. 20 illustrates a paddle head 186′ of a combinationtransvaginal probe 180′ that includes imaging transducer 182 and a HIFUtransducer 184 a. Both imaging transducer 182 and HIFU transducer 184 acomprise 1D phased array elements oriented so that the respectiveimaging and therapeutic ultrasound signals can be steered and focused insubstantially the same plane, i.e., in a plane aligned with alongitudinal axis of the combination transvaginal probe. The 1D phasedarray elements of HIFU transducer 184 a are generally semi-circular isshape, due to its slightly concave configuration.

[0108] In FIG. 21, a paddle head 192 of a combination transvaginal probe194 is illustrated. Paddle head 192 includes a two-dimensional (2D)phased array imaging transducer 196 and a 2D phased array HIFUtransducer 198. The 2D phased array elements of both the imagingtransducer and HIFU transducer can thus be electronically steered andfocused within a substantial conical volume, providing the clinician thecapability to electronically control the location of the target areathat is imaged and the location of the treatment site to which the HIFUwaves are administered.

[0109] Mice Study

[0110] A laboratory study has shown that uterine fibroid tumors in amouse can be treated completely, achieving nearly 100% shrinkage, usingHIFU therapy. An Abstract of a paper submitted to the American Journalof Obstetrics and Gynecology to describe this study is included below,with minor modifications.

[0111] The objective of the study was to investigate the potentialefficacy of high intensity focused ultrasound (HIFU) for the treatmentof uterine fibroid tumors. A total of 60 female athymic nude mice wereinoculated subcutaneously with 3-5×10⁶ ELT-3 cells, a uterine fibroidtumor cell line. Tumor development was monitored using subcutaneouscaliper measurements of the tumors. The HIFU probe was a concave,single-element high-power transducer, operating at a frequency of 3.5MHz, and an intensity of 2000 WM/cm². The HIFU treatment consisted ofscanning the tumors for 30-60 seconds, based on the tumor size. A singleHIFU-treatment resulted in a tumor reduction of 91% within one month ofthe treatment. Histological analysis of HIFU-treated tumors showedcoagulation necrosis, and nuclear fragmentation of tumor cells. It isthus concluded that the HIFU effectively reduced uterine fibroid tumorsize in a nude mouse model. Further studies are needed to assess thein-situ response of uterine fibroids to HIFU treatment.

[0112] This study presents an important result; uterine fibroids can betreated at least twice to achieve a desired tumor shrinkage percentage.Several treatments could provide an optimal outcome for the patient.Such method may be valuable for large tumors that may not shrink to adesired volume, with a single treatment.

[0113] EKER Rat Study

[0114] Another study has shown that HIFU therapy can cause shrinkage ofuterine fibroid tumors in a rat model (EKER rats). This study wasconducted on an in-situ model of the uterine fibroid. Sham-treatedanimals did not show any tumor shrinkage. Instead, their tumors grew toabout 85 times the volume at the time of treatment. In contrast,HIFU-treated animals showed tumor shrinkage of about 80% (20% of thevolume at the time of treatment, after 3 months). Of particular interestin the results obtained in this study is the response of individualanimals to the treatment. When tumors were completely treated, shrinkagewas not optimal, perhaps due to fibrosis of the necrotic tumor insteadof the absorption by the body. It should be noted that a histologicalanalysis has not been performed yet to provide a definitive conclusion.When tumors were incompletely treated, especially when areas of viabletumor existed around the HIFU lesion, shrinkage was optimal, withminimal fibrosis.

[0115] This study presents an important result; an effective tumorde-bulking with significant shrinkage may be provided by HIFU-treatmentprocedures that create scattered lesions in the tumor, to allow body'smacrophage absorption of the necrosis area, without fibrosis. Thisprocedure may be combined with the above procedure of multipletreatments to achieve complete shrinkage and/or optimal de-bulking to adesired volume.

[0116] Cytokine Study

[0117] Also investigated was the inflammatory response of the body toHIFU treatment, and its possible effect on tumor necrosis. A host ofcytokines (non-antibody proteins, released by macrophages (activelyphagocytic cells), on contact with a specific antigen and which act asintercellular mediators, as in the generation of immune response) areknown to be involved in such inflammatory response. It has been shownthat therapeutic ultrasound has a stimulatory effect on the productionof cytokines. The cytokine production is a signaling mechanism thatresults in attraction of more macrophages, and an enhanced immuneresponse.

[0118] This study presents an important implication. The inflammatoryresponse of the body to HIFU treatment may provide an enhanced rate oftumor shrinkage due to enhanced cytokine production. This mechanism mayprovide grounds for a treatment procedure that involves the productionof scattered HIFU lesions in the uterine fibroid tumor, and obtaining anoptimal tumor shrinkage due to enhanced immune response.

[0119] Synergistic Treatment

[0120] Synergistic effects of therapeutic ultrasound and anti-tumorcompounds may provide a mechanism for treatment for uterine fibroids,involving a combination therapy using both anti-tumor drugs and HIFU.This management has two possibilities, including the use HIFU with thedrugs currently available for uterine fibroids (GnRH agonists). Thesedrugs can shrink the fibroids temporarily. As soon they arediscontinued, the fibroids grow back to their original size. Since thesedrugs have side effects, they are primarily used for shrinking thefibroids before a myomectomy (surgical removal of the fibroids). HIFUtreatment may be performed at the time when maximal shrinkage of thetumors due to drugs has occurred, thereby fixing the tumor size andpreventing tumor re-growth. The second possibility is to use HIFU withthe new anti-tumor compounds which may offer further advantages.

[0121] Methods of Administering the HIFU Therapy

[0122] Several methods for administering HIFU therapy of uterinefibroids are envisioned. These include the treatment of the entire tumorin a single procedure. It has been observed that a complete tumortreatment (100% shrinkage) may be obtained using this method.Alternatively, the tumor may be treated in several sessions, withsufficient time between each session for the macrophages in thepatient's body to clear away the necrotic tissue resulting from theprevious treatment session, effectively debriding the treatment side andexposing remaining tumor tissue for the next HIFU therapy session. Ineach session, a remaining part of the tumor is treated. A complete tumortreatment (100% shrinkage) in all of the tumors treated using thismethod has been observed. Scattered HIFU lesions in a tumor may alsoprovide an optimal shrinkage, with minimal fibrosis. Several HIFUtherapy sessions may be needed to completely eradicate the tumor.Further, as noted above, the treatment of a tumor using a combination ofHIFU and drugs may yield synergistic results, particularly by beginningthe HIFU therapy when the maximum benefit of the drug therapy on thetumor has been realized.

[0123] Although the present invention has been described in connectionwith the preferred form of practicing it and modifications thereto,those of ordinary skill in the art will understand that many additionalmodifications can be made thereto within the scope of the claims thatfollow. Accordingly, it is not intended that the scope of the inventionin any way be limited by the above description, but instead bedetermined entirely by reference to the claims that follow.

The invention in which an exclusive right is claimed is defined by thefollowing:
 1. A method for using ultrasound to simultaneously image atarget area and to provide therapy to a treatment site disposed withinsaid target area, producing a lesion in a blood vessel that occludes ablood supply relative to a region, comprising the steps of: (a)providing: (i) a scanning ultrasonic transducer system adapted to scan atarget area and to provide imaging data for said target area; (ii) aprocessor adapted to process said imaging data; (iii) a display capableof providing a visual representation of said imaging data to a user; and(iv) a therapeutic ultrasonic transducer system adapted to provide wavesof high intensity focused ultrasound (HIFU) to said treatment site; (b)energizing said scanning ultrasonic transducer system to continuallyscan said target area to produce said imaging data; (c) displaying avisual representation of said imaging data to the user on the display toproduce a displayed target area; (d) selecting the treatment site fromwithin the displayed target area proximate a blood vessel supplyingblood to the region; and (e) directing the therapeutic waves of the HIFUat the treatment site with the therapeutic ultrasonic transducer system,said therapeutic ultrasonic transducer system being synchronizedrelative to the scanning ultrasonic transducer system such that anynoise in said imaging data arising from said therapeutic waves isshifted away from the treatment site in the displayed target area,enabling the treatment site to be observed in real time as thetherapeutic waves of the HIFU are administered to the treatment site,said therapeutic waves being of sufficient intensity to form a lesion inthe blood vessel that occludes the blood vessel, preventing blood fromcontinuing to flow into the region, so that oxygen and nutrientsconveyed by blood flowing through the blood vessel do not reach theregion.
 2. The method of claim 1, further comprising the steps of: (a)initially energizing the therapeutic ultrasonic transducer system at areduced energy level so as to produce a pulsed wave that is notenergetic enough to produce a therapeutic effect at the treatment site,but is sufficiently energetic to produce a change in an echogenicity oftissue at the treatment site, a focal point of the therapeuticultrasonic transducer system being visually apparent in the displayedtarget area visually represented on the display where the echogenicityof the tissue has thus been changed; (b) moving the focal point of thetherapeutic ultrasonic transducer system to a desired position; and (c)increasing the energy level of the therapeutic ultrasonic transducersystem to a therapeutic level to generate the therapeutic waves withsufficient energy to produce a desired therapeutic effect at the focalpoint.
 3. The method of claim 2, further comprising the step of: (a)storing the visual representation of the focal point in the displayedtarget area for the position at which the therapeutic waves of the HIFUare being administered; (b) reducing the energy level of the therapeuticultrasonic transducer system to the reduced level of the pulsed waveafter the desired therapeutic effect has been achieved at the focalpoint; (c) moving the focal point of the therapeutic ultrasonictransducer system to a different desired position to define a newtreatment site, said focal point be visually apparent in the displayedtarget area due the change in the echogenicity caused by the reducedlevel of the pulsed wave at the new treatment site in relationship tothe visual representation of the focal point stored in step (a) of thisclaim; (d) energizing said therapeutic ultrasonic transducer system;thereby producing the therapeutic waves of HIFU directed at the newtreatment site; and (e) repeating steps (a)-(d) of this claim until thetherapeutic waves of HIFU have been administered to all desiredtreatment sites, the visual representation of all focal points on thedisplay at which the therapeutic waves of the HIFU were previouslyadministered enabling positions of each new treatment sites to bereadily selected in relationship to previous treatment sites.
 4. Themethod of claim 1, further comprising the steps of: (a) monitoring thedisplayed target area on the display for any changes in an area outsidethe treatment site caused by the therapeutic waves of HIFU delivered tothe treatment site; and (b) de-energizing the therapeutic ultrasonictransducer system to prevent further changes to the area outside thetreatment site, even if the desired therapeutic effect has not yet beenachieved at the treatment site.
 5. The method of claim 1, furthercomprising the step of processing the imaging data to effect at leastone of: a scan conversion processing, a color flow processing, a Dopplerprocessing, a B-mode processing, and an M-mode processing.
 6. The methodof claim 1, wherein the target area is associated with a reproductivesystem of a mammalian female.
 7. The method of claim 6, wherein thetherapeutic waves of the HIFU are administered to produce a lesion inthe blood vessel to therapeutically affect a region that includes oneof: a uterine fibroid, an endometrial polyp, a follicular cyst, apolycystic ovary, a dermoid cyst, a corpus luteum cyst, an ectopicpregnancy, a cornual pregnancy, a multifetal pregnancy, a uterinemalformation, an endometrial hyperplasia, an adenomyosis condition, anendometriosis condition, an excessive bleeding condition, a placentalabruption, a fetal anomaly, and a twin-twin infusion.
 8. The method ofclaim 1, further comprising the step of: (a) providing a probeincorporating both the scanning ultrasonic transducer system and thetherapeutic ultrasonic transducer system and having a size and shapeadapted to be inserted through one of: (i) a human vaginal canal; (ii) ahuman rectum; (iii) a human abdominal cavity; and (iv) a laparoscopicdermal incision; (b) inserting the probe through a part of the humanbody through which it is adapted to be inserted; and (c) advancing theprobe until it is adjacent to the target area before energizing thetherapeutic ultrasonic transducer system.
 9. The method of claim 1,wherein said therapeutic ultrasonic transducer system generates thetherapeutic waves of the HIFU at frequencies within the range of 0.5 MHzto 10 MHz.
 10. The method of claim 2, further providing a blood solublematerial that has a high vapor pressure, and further comprising the stepof administering the blood soluble material to the selected blood vesselbefore initially energizing the therapeutic ultrasonic transducer systemat a reduced energy level, such that bubbles produced by the interactionof the blood soluble material and the therapeutic wave at a focal pointof the therapeutic wave are detected by the scanning ultrasonictransducer system..
 11. The method of claim 1, wherein the therapeuticultrasonic transducer system comprises a phased array of ultrasonictransducers, said step of directing the therapeutic waves comprising thestep of varying a position of a focal point of the phased array.
 12. Themethod of claim 11, wherein the phased array of ultrasonic transducerscomprises a plurality of concentric transducer elements.
 13. The methodof claim 1, wherein the therapeutic ultrasonic transducer systemincludes a vibrating element, further comprising the step of energizingthe vibrating element to vary a focal point of the therapeuticultrasonic transducer system.
 14. The method of claim 13, wherein thestep of energizing the vibrating element comprises the step of causingthe therapeutic ultrasonic transducer system to vibrate with a frequencyin the range of 1 to 5 Hz so that the position of the focal point withinthe target area is varied.
 15. The method of claim 13, wherein the stepof energizing the vibrating element comprises causing the therapeuticultrasonic transducer system to vibrate with a frequency in the range of10 to 50 Hz, thereby increasing an amount of energy applied to thetreatment site while avoiding undesired cavitational effects.
 16. Themethod of claim 1, further comprising the step of causing a focal pointof the therapeutic ultrasonic transducer system to be varied within thetarget area in a random manner.
 17. The method of claim 1, whereinadministering the therapeutic waves to produce the lesion cause at leastone of: arresting a bleeding at the treatment site, preventing bleedingat the treatment site, and causing tissue necrosis at the treatmentsite.
 18. The method of claim 17, wherein the necrosis of tissue at thetreatment site is caused by cavitation effects.
 19. The method of claim1, wherein a desired therapeutic effect of administering the therapeuticwaves is one of an ablation of tissue at the treatment site and ahemostasis at the treatment site.
 20. A method for using ultrasound tovisualize and to provide therapy to a treatment site within a targetarea, such that an image is displayed to a clinician in real time, tocontinually provide feedback to the clinician relating to a focal pointof therapeutic waves of high intensity focused ultrasound (HIFU) and achange in the treatment site, said method enabling a plurality oflesions to be produced in blood vessels supplying a region to occludeblood flow through the blood vessels into the region, comprising thesteps of: (a) providing: (i) a scanning ultrasonic transducer systemadapted to scan the target area with a probe and to provide imaging datafor said target area; (ii) a processor adapted to process said imagingdata; (iii) a display that provides a visual representation of saidimaging data to a clinician; and (iv) a therapeutic ultrasonictransducer system adapted to provide the pulsed waves of the HIFU fromthe probe; (b) positioning the probe of the scanning ultrasonictransducer system and energizing the scanning ultrasonic transducersystem so that an image comprising a visual representation of the targetarea is continually generated on the display as a displayed target area;(c) directing the therapeutic ultrasonic transducer system at aprospective treatment site that is within the displayed target area; (d)initially energizing the therapeutic ultrasonic transducer system at areduced energy level that is so as to produce a pulsed wave that is notenergetic enough to produce a therapeutic effect at the treatment site,but is sufficiently energetic to produce a change in an echogenicity oftissue at the treatment site, a focal point of the therapeuticultrasonic transducer system being visually apparent in the displayedtarget area visually represented on the display where the echogenicityof the tissue has thus been changed; (e) moving the focal point of thetherapeutic ultrasonic transducer system to a desired position on ablood vessel; (f) increasing the energy level of the therapeuticultrasonic transducer system to a therapeutic level to produce thetherapeutic waves with sufficient energy to produce a lesion in theblood vessel at the focal point; and (g) repeating steps (c) through (f)for treatment sites comprising each additional blood vessel from theplurality of blood vessels, until blood flow into the region issubstantially terminated.
 21. The method of claim 20, further comprisingthe step of: (a) storing the visual representation of the focal point inthe displayed target area for the position at which the therapeuticwaves of the HIFU are being administered; (b) reducing the energy levelof the therapeutic ultrasonic transducer system to the reduced level ofthe pulsed wave after the desired therapeutic effect has been achievedat the focal point; (c) moving the focal point of the therapeuticultrasonic transducer system to a different desired position within thedisplayed target area to define a new treatment site, said focal pointbe visually apparent in the displayed target area due the change in theechogenicity caused by the reduced level of the pulsed wave at the newtreatment site in relationship to the visual representation of the focalpoint stored in step (a) of this claim; (d) energizing said therapeuticultrasonic transducer system; thereby producing the therapeutic waves ofHIFU directed at the new treatment site; and (e) repeating steps (a)-(d)of this claim until the therapeutic waves of HIFU have been administeredto all desired treatment sites, the visual representation of all focalpoints on the display at which the therapeutic waves of the HIFU werepreviously administered enabling positions of each new treatment sitesto be readily selected in relationship to previous treatment sites. 22.The method of claim 20, further comprising the step of monitoring thedisplayed target area to determine with the desired effect has beenobtained at a current treatment site before administering thetherapeutic waves of the HIFU to a new treatment site.
 23. The method ofclaim 20, further comprising the step of processing the imaging data toeffect at least one of: a scan conversion processing, a color flowprocessing, a Doppler processing, a B-mode processing, and an M-modeprocessing.
 24. The method of claim 20, wherein the target area is thereproductive system of a mammalian female, and the therapeutic waves ofthe HIFU are administered to the region to treat at least one of: auterine fibroid, an endometrial polyp, a follicular cyst, a polycysticovary, a dermoid cyst, a corpus luteum cyst, an ectopic pregnancy, acornual pregnancy, a multifetal pregnancy, a uterine AV malformation, anendometrial hyperplasia, an adenomyosis condition, an endometriosiscondition, and an excessive bleeding condition.
 25. The method of claim20, wherein the probe has a size and shape adapted to be insertedthrough one of: a vaginal canal, a rectum, an abdominal cavity, and alaparoscopic incision, further comprising the steps of: (a) insertingthe probe into an area of the body through which the probe is adapted tobe inserted; and (b) advancing the probe until the probe is adjacent tothe target area.
 26. The method of claim 20, wherein said therapeuticultrasonic transducer system generates the therapeutic waves of the HIFUat frequencies within the range of 0.5 MHz to 10 MHz.
 27. The method ofclaim 26, wherein said therapeutic ultrasonic transducer systemgenerates the therapeutic waves of the HIFU at frequencies within therange of 3.4 MHz to 3.6 MHz.
 28. The method of claim 20, wherein thetherapeutic ultrasonic transducer system comprises a phased array oftransducer elements that enable focusing of the therapeutic waves of theHIFU.
 29. The method of claim 28, wherein the phased array of transducerelements are arranged in a concentric pattern.
 30. The method of claim20, wherein the therapeutic ultrasonic transducer system includes avibrating element, further comprising the step of energizing thevibrating element to vibrate the therapeutic ultrasonic transducersystem, so that a focal point of the therapeutic ultrasonic transducersystem is varied.
 31. The method of claim 30, wherein the step ofenergizing the vibrating element comprises causing the therapeuticultrasonic transducer system to vibrate at a frequency in the range offrom 1 to 50 Hz.
 32. The method of claim 20, wherein the desired effectproduced by causing lesions that occlude the plurality of blood vesselscomprises one of a cauterization of tissue, a necrosis of tissue, and anablation of tissue at the treatment site.
 33. A method for treating atumorous growth by damaging selected regions within the tumorous growth,comprising the steps of: (a) providing: (i) a scanning ultrasonictransducer system adapted to scan a target area and to produce imagingdata for said target area; (ii) a processor adapted to process saidimaging data; (iii) a display that is adapted to present a visualrepresentation of said imaging data; and (iv) a high intensityultrasonic transducer system that is adapted to produce high intensityfocused ultrasound (HIFU) capable of damaging tissue within the tumorousgrowth; (b) positioning and energizing the scanning ultrasonictransducer system to continually produce an image of the target area onthe display comprising a displayed target area; (c) selecting atreatment site within the tumorous growth that is visually representedin the displayed target area; (d) focusing pulsed HIFU produced by thehigh intensity ultrasonic transducer system on the treatment site thatwas selected to damage tissue within the tumorous growth; (e) focusingthe high intensity ultrasonic transducer system onto a differentselected region within the tumorous growth; and (f) repeating steps (d)through (e) until a desired pattern of damaged areas in the tumorousgrowth has been achieved.
 34. The method of claim 33, further comprisingthe step of monitoring a condition of each treatment site in thetumorous growth to determine when sufficient tissue has been damagedbefore moving to a new treatment site.
 35. The method of claim 33,further comprising the step of repeating steps (a) to (f) atspaced-apart intervals of time, to enable any tissue in the tumorousgrowth that was destroyed by the HIFU to be removed by natural bodilyprocesses, until the tumorous growth has been substantially eliminated.36. The method of claim 33, further comprising the steps of: (a)initially energizing the high intensity ultrasonic transducer system ata reduced energy level so as to produce a pulsed wave that is notenergetic enough to damage the tissue at the treatment site, but issufficiently energetic to produce a change in an echogenicity of thetissue at the treatment site, a focal point of the high intensityultrasonic transducer system being visually apparent in the displayedtarget area visually represented on the display where the echogenicityof the tissue has thus been changed; (b) moving the focal point of thehigh intensity ultrasonic transducer system within the displayed targetarea to a desired position; and (c) increasing the energy level of thehigh intensity ultrasonic transducer system to a therapeutic level toproduce therapeutic waves with sufficient energy to damage the tissue ofthe tumorous growth at the focal point.
 37. The method of claim 33,further comprising the step of de-energizing the high intensityultrasonic transducer if the displayed target area shows that anundesired change has taken place to tissue in the target area, even if adesired level of damage to tissue within the tumorous growth has not yetbeen achieved.
 38. The method of claim 33, further comprising the stepof processing the imaging data comprises to effect at least one of: acolor flow processing, a Doppler processing, a B-mode processing, and anM-mode processing.
 39. The method of claim 33, wherein the target areaincludes the reproductive system of a mammalian female, and wherein thetumorous growth is one of a uterine fibroid, an endometrial polyp, afollicular cyst, a polycystic ovary, a dermoid cyst, and a corpus luteumcyst.
 40. The method of claim 33, further comprising the step ofproviding a probe incorporating both the scanning ultrasonic transducersystem and the high intensity ultrasonic transducer system having a sizeand shape adapted to be inserted through one of a vaginal canal, arectum, an abdominal cavity, and a laparoscopic incision.
 41. The methodof claim 33, wherein said high intensity ultrasonic transducer systemgenerates the therapeutic waves of the HIFU at frequencies within therange of 0.5 MHz to 10 MHz.
 42. The method of claim 36, furtherproviding a blood soluble material that has a high vapor pressure, andfurther comprising the step of administering the blood soluble materialto the treatment site before initially energizing the therapeuticultrasonic transducer system at a reduced energy level, such thatbubbles produced by the interaction of the blood soluble material andthe therapeutic wave at a focal point of the therapeutic wave aredetected by the scanning ultrasonic transducer system.
 43. The method ofclaim 33, wherein the damage to tissue within the tumorous growth isachieved by causing one of: cauterization of the tissue, necrosis of thetissue, and ablation of the tissue.
 44. The method of claim 35, whereinmacrophages remove the tissue that was destroyed from the tumorousgrowth.
 45. A system for simultaneously using ultrasound for bothimaging and therapeutic purposes, enabling a lesion to be produced in ablood vessel to occlude blood flow, comprising: (a) an ultrasonicscanning transducer disposed on a probe, said ultrasonic scanningtransducer being adapted to generate an ultrasonic scanning wave and toreceive the ultrasonic scanning wave after it is reflected from a targetarea in a patient's body, producing a signal that is useful for derivingimaging data for the target area; (b) a processor electrically coupledto the scanning ultrasonic transducer system capable to receive thesignal, said processor processing the signal to produce the imagingdata; (c) a display electrically coupled to the processor, said displaypresenting a visual representation of the imaging data; (d) atherapeutic ultrasonic transducer disposed on the probe and adapted togenerate a pulsed high intensity focused ultrasonic (HIFU) therapeuticwave directed at a treatment site within the target area; (e) a controlcircuit electrically coupled to the therapeutic ultrasonic transducersystem that synchronizes generation of the pulsed HIFU therapeutic waverelative to the ultrasonic scanning wave produced by the scanningultrasonic transducer system, such that any noise within the imagingdata arising from the pulsed HIFU therapeutic wave is shifted within thevisual representation of the imaging data appear outside the treatmentsite, said control circuit providing sufficient energy to thetherapeutic ultrasound transducer to cause a lesion in a blood vesselthat is included in the visual representation of the target area, sothat blood flow through the blood vessel to a region is occluded by thelesion; and (f) a power supply electrically coupled to supply anelectrical current to energize the scanning ultrasonic transducersystem, the therapeutic ultrasonic transducer system and the controlcircuit.
 46. The system of claim 45, wherein the processor processes thesignal to effect at least one of: a color flow processing, a Dopplerprocessing, a B-mode processing, and an M-mode processing, saidprocessor storing a portion of the imaging data that defines eachposition at which the pulsed HIFU therapeutic wave was focused on thetreatment site.
 47. The system of claim 45, wherein the target area isthe reproductive system of a mammalian female.
 48. The system of claim47, wherein the pulsed HIFU therapeutic wave therapeutic wave isemployed to treat one of: a uterine fibroid, an endometrial polyp, afollicular cyst, a polycystic ovary, a dermoid cyst, a corpus luteumcyst, an ectopic pregnancy, a cornual pregnancy, a multifetal pregnancy,a uterine malformation, an endometrial hyperplasia, an adenomyosiscondition, an endometriosis condition, and an excessive bleedingcondition.
 49. The system of claim 45, wherein the probe has a size andshape adapting it to being inserted into and manipulated within in ahuman vaginal canal.
 50. The system of claim 49, wherein the probecomprises a handle having the ultrasonic scanning transducer and thetherapeutic ultrasonic transducer mounted on a distal end of the handle.51. The system of claim 50, wherein the therapeutic transducer ismounted to the handle with a pivot joint, enabling a disposition of thetransducer relative to the handle to be adjusted by manipulating thetherapeutic transducer about the pivot joint.
 52. The system, of claim50, wherein the therapeutic transducer includes a fluid filled cavitythat couples ultrasonic wave emitted by the therapeutic transducer tothe treatment site.
 53. The system of claim 45, wherein probe has a sizeand shape adapting it to being inserted into and manipulated within ahuman rectum.
 54. The system of claim 45, wherein the therapeuticultrasonic transducer generates frequencies within the range of 0.5 MHzto 10 MHz.
 55. The system of claim 45, wherein the therapeuticultrasonic transducer generates frequencies within the range of 3.4 MHzto 3.6 MHz.
 56. The system of claim 45, wherein the therapeuticultrasonic transducer comprises a phased array of transducer elementsthat enables a focal point of the therapeutic ultrasonic transducer tobe selectively varied.
 57. The system of claim 56, wherein the phasedarray of transducer elements is configured in a concentric pattern. 58.The system of claim 45, wherein the therapeutic ultrasonic transducersystem comprises a vibrating element that when energized causes a focalpoint of the therapeutic ultrasonic transducer system to be randomlyvaried within the target area.
 59. The system of claim 58, wherein thevibrating element vibrates with a frequency in the range of 1 to 5 Hz,variation of the focal point preventing undesired heating of tissue notassociated with the treatment site.
 60. The system of claim 58, whereinthe vibrating element vibrates with a frequency in the range of 10 to 50Hz and increases an amount of energy applied to the treatment site whileavoiding undesired cavitational effects.
 61. A probe for administeringultrasound therapy from within a vaginal canal of a patient, saidtherapy being administered to a treatment site within the patient's bodyand outside the vaginal canal, comprising: (a) an elongate supportingstructure having a distal end and a proximal end, said elongatesupporting structure including a section at its proximal end that isadapted to be grasped and manipulated by a clinician to at leastinitially position the elongate supporting structure at a desiredlocation within the vaginal canal of the patient; (b) an imagingtransducer disposed at the distal end of the elongate supportingstructure, said imaging transducer being adapted to emit ultrasoundimaging pulses when excited by an imaging signal for use in producing animage of a target area in the patient's body; (c) a high intensityfocused ultrasound (HIFU) transducer disposed at the distal end of theelongate supporting structure, proximate to the imaging transducer andsized and shaped to fit within the vaginal canal, said HIFU transducerhaving an aperture through which HIFU waves are transmitted, saidaperture being of a sufficient size to produce therapeutic HIFU waves,so that the therapeutic HIFU waves have sufficient intensity remainingupon reaching the treatment site after being attenuated by their passagethrough up to 6 cm of intervening tissue, to achieve a desiredtherapeutic effect, while said therapeutic HIFU waves do not have somuch intensity when emitted by the HIFU transducer as to damage adjacenttissue through which the therapeutic HIFU waves initially propagatetoward the treatment site; and (d) means for directing the therapeuticHIFU waves at the treatment site within the target area, said HIFUtransducer being energized to render the HIFU therapy while the imagingtransducer is energized to provide a signal for imaging the target area.62. The probe of claim 61, wherein a maximum circumference of theaperture of the HIFU transducer, measured in a plane that is generallytransverse to a longitudinal axis of the elongate supporting structure,is about 10.6 cm.
 63. The probe of claim 61, wherein the desiredtherapeutic effect produced at the treatment site by the therapeuticHIFU waves comprises at least one of the following: (a) damage toundesired tissue; (b) hemostasis of a blood vessel; (c) necrosis ofundesired tissue; (d) ablation of undesired tissue; and (e) obstructionof a blood vessel.